Vaccines represent the major success of immunology and have spared countless numbers of people from infections. Despite this success, we understand little about how effective vaccines stimulate protective immune responses. We surmise that understanding the modus operandi of vaccines in healthy people and understanding their shortcomings by studying hypo-responsive people will permit us to unravel the immunological principles of vaccination. Three vaccines will be studied in great detail: inactivated influenza vaccine and hepatitis B vaccine with either alum as the traditional adjuvant (Engerix) or with CPGoligonucleotide (Heplisav). We surmise that systems biology approaches will permit us to gain a comprehensive view of the immunobiology associated with a potent response to vaccination. This will lead to the identification of biomarker signatures indicative of the quality of vaccine-induced antibody responses. This, in turn, will facilitate the rational design and development of novel improved vaccines. Our preliminary studies performed with 24 healthy volunteers indicate that three commercially available vaccines: Fluzone (influenza), Pneumovax and Engerix alter the blood cell composition and transcriptome in completely different ways. These preliminary results support our proposed strategy. They demonstrate that the different vaccines, which are able to induce protective humoral responses, mobilize different immune effectors. We propose five highly integrated projects which will be supported by seven cores. Our key deliverables will include: i) Increased knowledge on vaccine-induced immune system alterations in dendritic cells, monocytes and T follicular helper cells;ii) Biomarkers of humoral immune responses;iii) An ex vivo assay for prediction of immune response to vaccination;iv) Tools to assess vaccine-activated cells;v) A systems biology analysis of two adjuvants: Alum and CPG-Oligonucleotides;vi) A systems biology analysis of the response to vaccine in patients with altered immune systems;and vii) An Immunochip, or focused microarray, for the assessment of vaccine immune efficacy. RELEVANCE (See instructions): Vaccines represent the major success of immunology and yet we understand little about how effective vaccines stimulate protective immune responses. Our preliminary studies indicate that three commercially available vaccines alter the blood cell composition and transcriptome in completely different ways to induce protective immunity. We propose five highly integrated projects supported by seven cores to characterize vaccine-induced immune system alterations using a systems biology approach. PROJECT 1: Systems Biology Approach to Analysis of Vaccine Response in Healthy Individuals Project Leader: Banchereau, J PROJECT 1 DESCRIPTION (provided by applicant): Vaccines represent the major success of immunology and have spared countless numbers of people from infections. Despite their success, we understand little about how effective vaccines stimulate protective immune responses. Three classes of vaccine can be distinguished: i) highly effective vaccines such as yellow fever, measles and smallpox;ii) good vaccines which yield protective immunity in a majority of people including seasonal Influenza (Flu) vaccines, hepatitis B and pneumovax;and iii) vaccines which are largely not effective at the current time including HIV-AIDS, malaria, and Hepatitis C. We surmise that understanding the modus operandi of good vaccines in healthy people and understanding their shortcomings by studying hypo-responsive people will permit us to unravel the immunological principles of vaccination. Two recent developments promise to yield such understanding: i) the appreciation of the crucial role of dendritic cells in inducing and tuning the immune responses and ii) advances in high-throughput molecular profiling technologies underlying systems biology approaches. We hypothesize that a systems biology analysis will yield a comprehensive view of the immune alterations associated with a potent response to flu vaccination. We further hypothesize that efficient vaccination is associated to the early activation of antigen presenting cells. Our goal is to identify early biomarkers of effective antibody responses to flu vaccination. Four aims are proposed to meet this goal: Aim 1: To establish the baseline immune profiles in healthy subjects. Aim 2: To establish the immune profiles of Flu vaccination in healthy subjects. Aim 3: To identify the molecular signatures of DC subset(s) in response to Flu vaccination. Aim 4: To identify the molecular signatures of activated monocytes in response to Flu vaccination. RELEVANCE (See instructions): Despite the success of vaccines, we understand little about how effective ones stimulate protective immune responses. We will study how the flu vaccine generates effective antibody responses. The goal is to identify the immune responses elicited by effective vaccines so that vaccines that aren't as effective can be improved. To do this, we will vaccinate healthy people with the flu vaccine and monitor their immune response following the vaccination.